Engineering topics

Stein-Schabes, Jaime A.

Publications and source records attributed to Stein-Schabes, Jaime A..

4 records

NASA NTRS1988

Gauged Q-balls

Classical non-topological soliton configurations are considered within the theory of a complex scalar field with a gauged U symmetry. Their existence and stability against dispersion are demonstrated and some of their properties are investigated analytically and numerically. The soliton configuration is such that inside the soliton the local U symmetry is broken, the gauge field becomes massive and for a range of values of the coupling constants the soliton becomes a superconductor pushing the charge to the surface. Furthermore, because of the repulsive Coulomb force, there is a maximum size for these objects, making impossible the existence of Q-matter in bulk form. Also briefly discussed are solitons with fermions in a U gauge theory.

Lee, Kimyeong↗

NASA NTRS1988

On the locality of the no hair conjection and the measure of the universe

The reently proposed proof by Jensen and Stein-Schabes of the No Hair Theorem for inhomogeneous spacetimes is analyzed, putting a special emphasis on the asymptotic behavior of the shear and curvature. It is concluded that the theorem only holds locally, and the minimum size a region should be is estimated in order for it to inflate. The assumptions used in the theorem are discussed in detail. The last section speculates about the possible measure of the set of spacetimes that would undergo inflation.

Pacher, Tibor↗

NASA NTRS1988

Inflation in a renormalizable cosmological model and the cosmic no hair conjecture

The possibility of having inflation in a renormalizable cosmological model is investigated. The Cosmic No Hair Conjecture is proved to hold for all Bianchi types except Bianchi IX. By the use of a conformal transformation on the metric it is shown that these models are equivalent to the ones described by the Einstein-Hilbert action for gravity minimally coupled to a set of scalar fields with inflationary potentials. Henceforth, it is proven that inflationary solutions behave as attractors in solution space, making it a natural event in the evolution of such models.

Maeda, Kei-Ichi↗

NASA NTRS1987

A no hair theorem and the problem of initial conditions

It is shown that under very general conditions, any inhomogeneous cosmological model with a positive cosmological constant that can be described in a synchronous reference system will tend asymptotically in time towards the de Sitter solution. This renders the problem of initial conditions less severe.

Jensen, Lars Gerhard↗